Jennifer Drumm had the worst headache of her life. The pain was so severe that as she arrived at the Charles Cole Memorial Hospital in Coudersport, Pennsylvania, an emergency room doctor suspected she had a cerebral hemorrhage, which could quickly turn deadly. He ordered a CT (computed tomography) scan of Drumm’s brain.

It was around 6 p.m. on a Friday night. Like many small hospitals, the rural facility did not always have a radiologist on site to interpret scans. Instead, the hospital had a contract with an outside company, Chambersburg Imaging Associates, to read them. In a process known as teleradiology, the hospital took the CT, then sent a digital version by computer, much like sending an email, to a radiologist four hours away in Chambersburg, Pennsylvania. He ruled out a hemorrhage but found a mass in Drumm’s left temporal lobe—a possible tumor.

The diagnosis was frightening but not immediately life-threatening. So, after scheduling a follow-up with an oncologist, the ER gave Drumm painkillers and discharged her. At 9 p.m., Drumm, a 30-year-old computer technician, drove home. But by 4:30 a.m., after a night in tears from pain, she had called an ambulance and was back in the hospital, according to court records obtained by self. The ER doctor ordered a more detailed CT, using contrast dye.

That might have caught the true problem, if only Drumm’s doctor and radiologist had talked over the results. And up until a decade or so ago, that’s what would have happened. “In the old days, the radiology suite was right next to the ER, so the radiologist would walk past the patient on his way to read the scan,” says Lauren Ellerman, a personal-injury attorney in Roanoke, Virginia, who has handled radiology cases. Today, that image of doctors conferring in front of a backlit X-ray is as outdated as Marcus Welby.

With the now common use of teleradiology, the doctors who read your scans may well be across town, several states over or on the other side of the world. And instead of discussing what they see with your M.D., the often far-flung radiologists may send only written reports with little or no interaction. The result can resemble a perilous game of telephone.

In Drumm’s case, the hospital sent a digital copy of her new scan to Chambersburg Imaging. Presumably because of the predawn hour, Chambersburg then sent the film to a subcontracting company that had radiologists standing by in different time zones.

At 6:30 a.m. that Saturday, teleradiologist Edward Wong, M.D., opened Drumm’s file. Dr. Wong’s employer, Virtual Radiologic Consultants, was headquartered in Minnesota. Dr. Wong was licensed to practice medicine in Pennsylvania. But as he studied the images of Drumm’s head, he was at his home in Hong Kong. He saw the mass on his computer—and something more. The contrast dye revealed a ring around the mass, something Dr. Wong noted in his report for the ER. But he did not state what the ring could mean: a buildup of fluid or pus in the brain known as an abscess—an emergency that is almost always fatal if untreated.

The baton pass of films in cyberspace, from Coudersport to Chambersburg to Hong Kong, seemed to lead each physician to assume that someone else was connecting the dots. The emergency room doctor who read Dr. Wong’s report never spoke with him; he later admitted that he did not know the significance of the ring yet didn’t ask. Come Saturday, yet another radiologist working for Chambersburg Imaging read Drumm’s second CT. But he, too, did not contact the ER because he knew Dr. Wong’s report had been sent there, and he agreed with the findings his colleague had made, court documents reveal.

With no radiologists raising the alarm, the ER had discharged Drumm again. On Sunday, her parents rushed to her side from Iowa, planning to bring their daughter to her follow-up at the hospital the next day. But early Monday morning, they found her unconscious on the bathroom floor. Her abscess had ruptured.

Drumm spent the next 11 weeks in a coma, with shunts draining the fluid from her brain. She survived—but with permanent damage to her memory, intellect and ability to function. On Drumm’s behalf, her parents sued the hospital, the radiology contractors and six doctors involved in her care during that four-day period in 2005, although all have denied that their actions were negligent. The resulting settlement is confidential, and none of the parties was allowed to comment for this story.

“I know I’m different, but I can’t say how,” Drumm told a neuropsychologist hired to assess her for her case. Her family told the neuropsychologist that Drumm’s head injury had made her childlike in her vulnerability, with an exaggerated sense of humor and less inhibition. She talks animatedly to strangers in the mall, they said, and once wandered into a hotel hallway wearing only a top and no underwear. At 36 years old, Drumm cannot live on her own and will likely never return to work.

If you’ve had an X-ray, CT, magnetic resonance imaging (MRI) or any other scan in recent years, there’s a good chance its analysis—like so many other tech services—was outsourced. “The majority of hospitals use teleradiology in one form or another,” says Jonathan Linkous, CEO of the American Telemedicine Association in Washington, D.C. Facilities may have their own radiologists interpret scans remotely from home or offices, hire an outside company to read some of the scans, or outsource the whole department—meaning that no one involved in reading your scan works for the hospital.

To be sure, teleradiology has significant benefits. As Linkous notes, only the largest medical centers can afford to keep staff radiologists standing by at all hours. Smaller hospitals such as the one Drumm went to often cannot—yet urgent car accidents and illnesses happen every hour of the day, and every minute counts. With the advent of teleradiology, hospitals can connect with radiologists from nations in different time zones, including India, Israel and Australia. Typically, an overseas radiologist will do a preliminary read during off-hours, with a U.S. radiologist doing a final read the next day. In a few recent cases, Linkous says, patients have sued hospitals for not using teleradiologists after-hours, instead leaving the job to general physicians with less training in interpreting scans.

Although teleradiology can improve care by allowing access to specialists, a self investigation found that it also opens the door to confusion, errors and outright fraud. In the shuffle of reporting between remote strangers, crucial information can get lost, with reports never relayed, winding up in the wrong file or arriving after a patient has been discharged. Radiologists may also lack the context necessary to understand what they are seeing. In Fairfax, Virginia, last year, a jury awarded $1.25 million to the family of Hector Alvarez, a tech specialist who died after a tear in his esophagus was missed by the teleradiologist in a neighboring city who reviewed his CT. Alvarez had developed chest pain after eating a piece of meat—yet his doctors never passed along this fact, which suggested the food had caught in his throat and torn it.

Tracey Ehlen, 35, and her brother, Scott DeNoyer, 38, say the same poor communication doomed their mother in 2007, after she checked into the ER at Barnes-Jewish St. Peters Hospital in St. Peters, Missouri. Two days earlier, Deborah Icenhower, 55, had undergone a hysterectomy at a different hospital, suffering heavy bleeding during what is normally a routine operation. Now she was doubled over with a sharp pain in her chest.

Doctors sent for a chest CT, but because of the late hour, a radiologist in a nearby county interpreted it. Icenhower had told the emergency room doctors about her recent surgery, but the hospital failed to pass along an adequate history, her children would later allege in a lawsuit. The radiologist might have used this context to conclude that Icenhower’s surgical complications weren’t over. Instead, she found nothing urgent.

At 10:30 a.m., the hospital’s staff radiologist read the scan from the night before and saw something completely different: Icenhower was bleeding internally and needed immediate attention. But it was too late. She had died nearly five hours earlier, at 5:45 a.m. Ehlen and DeNoyer are suing the hospital, three doctors and the teleradiologist, all of whom deny any wrong­doing. “Everything is so specialized, but nobody does anything in a team,” says Lyle Warshauer, a lawyer in Atlanta who has represented patients harmed by teleradiology mix-ups. “It is a very unusual situation where a radiologist will pick up the phone.”

Perhaps most troubling: How do you know who is reading your scans? Ideally, a qualified radiologist would see them, or at least a physician with extra training in the field. But doctors are expensive, and unethical companies can reap profits by having lower-paid, unqualified technicians read scans. Radiologists warn of the potential for “ghosting,” an illegal practice whereby a doctor simply rubber-stamps the reading by a technician without giving it so much as a glance. Doctor’s electronic “signatures” on radiology reports are digitized, too, so it can be easy for techs to forge them. “Most people assume that images are going to be read in the hospital,” says Arl Van Moore, M.D., former president of the American College of Radiology (ACR) in Reston, Virginia. That’s usually not the case, and “there is no way for the patient to know if someone putting his name on the report has actually read it.”

Miriam Mizell had no reason to think twice about who analyzed the routine mammogram she got in 2009 from Perry Hospital, a 45-bed hospital in the quiet bedroom community of Perry, Georgia. And happily, a letter informed her the results were negative—Mizell, 63, had already had colorectal cancer and certainly didn’t need another ailment to combat.

Then, in April 2010, a hospital representative called with an unusual special offer: “We want you to come in for another mammogram—tomorrow.” Mizell was told she had been randomly selected by the hospital to help check its new digital mammography equipment, court documents state. She didn’t question the story. “I am a very literal person,” she says. “You tell me something, I believe it.” Mizell got the scan—and unlike with her earlier routine screening, a breast cancer specialist was right there waiting to read it. Lo and behold, he spotted something right behind her nipple. Mizell had early-stage carcinoma in situ.

As Mizell was confronting this bad news, a story broke in the local media: Nearly 1,300 mammography scans at Perry Hospital had never been read, as useless as if they’d been tossed in the garbage. Over the course of 14 months, a radiology technician had accessed the computer, used confidential PIN codes to crib doctors’ electronic signatures and generated letters to patients telling them their scans were all clear. But 10 of the women, including Mizell, had scans that revealed cancer. And the hospital knew it, court documents allege: The free screening offer had been a ploy to diagnose Mizell and the other women while concealing the initial fraud.

Soon the hospital’s position emerged: The technician, Rachael Michelle Rapraeger, had acted alone for motives known only to her. A grand jury would eventually indict her on 10 counts of reckless conduct and 10 more of computer forgery—one count for each of the women with cancer. “She must have just flipped,” a former colleague says. “I don’t know any other way to explain it.”

Rapraeger has vigorously maintained her innocence and pleaded not guilty. And as the victims, including Mizell, hired lawyers, the questions deepened. Who was minding the store? Techs like Rapraeger worked for Perry Hospital, but the doctors named on her phony reports did not. They worked for a contractor, Ali Shaikh, M.D., who staffed and ran the department through his company, Universal Radiology Consultants in Warner Robins, Georgia. And the doctor working for that contractor who had supposedly read and signed off on Mizell’s first mammogram had left the hospital—and Dr. Shaikh’s employment—almost eight months before the scan was done. This was a red flag—as was the fact that Rapraeger had entered results for some 100 mammograms in as little as 10 minutes. Based on a study at Northwestern University, the average radiologist would take at least that long to interpret only four mammograms.

One radiologist who worked for Universal Radiology Consultants at another hospital in Georgia said that he saw patient safety compromised. When women had worrisome mammograms, he witnessed technicians taking follow-up images without direct supervision from radiologists, flouting ACR guidelines. The former employee says he also worked alongside a part-time radiologist who likely cost the company less than a full-time M.D. but who made a series of errors, some life-threatening. He notified Dr. Shaikh but says “he wanted to continue to let the offending radiologist work as if he didn’t know about it.” Dr. Shaikh denies all of his former employees’ assertions.

Meanwhile, Perry Hospital told Mizell that her original scan had vanished, her complaint alleges. Two other women were told the same thing. But if the scans were lost, how could the hospital have known they were positive for breast cancer? “They say it was one woman acting alone, but there is more behind this than what I know,” Mizell told self last spring. “I was lied to repeatedly.” (Perry Hospital says it reached out to all 1,289 women whose scans went unread for retesting, and the hospital denied the allegations in Mizell’s suit. Dr. Shaikh and his company were dropped from the case; Mizell has now settled and is silenced by a confidentiality agreement.)

As extraordinary as what happened in Perry might seem, only 100 miles away prosecutors were unraveling a similar incident at nearly the same time. Between May 2007 and January 2008, teleradiologist Rajashakher Reddy, M.D., signed off on more than 70,000 scans from hospitals in Alabama, Florida, Georgia, Idaho and New York without any licensed radiologists’ looking at them, according to the jury that convicted him this past July.

Reddy Solutions Incorporated in Atlanta, which read scans from more than 15 hospitals, increased profits by handing images over to assistants instead of doctors, says prosecutor Justin Anand, an assistant U.S. attorney in Atlanta for the Northern District of Georgia. The bottom-line business model “created the temptation to get more clients and cut corners by not hiring enough doctors to get the images read right,” Anand says. Testimony alleged that Dr. Reddy, who faces up to 20 years in prison for each of 32 counts of fraud and obstruction, changed passwords to stop some hospitals from accessing disputed scans, so no one can identify the victims.

Fraud was not confined to Reddy Solutions, says an independent radiologist in Atlanta who worked for Dr. Reddy. She says two other firms she worked with used her name or electronic signature on scans she’d never read and then presumably billed for them. In one case, she learned this when a postal inspector and an FBI agent showed up at her house asking about some of the suspicious bills. Luckily, the agents agreed that she had been a victim of the scam, not a perpetrator.

The Atlanta radiologist also says that people in India have emailed her repeatedly offering to make radiology reports for cut-rate fees. Passing off the Indian reads as her own would allow her to bill for more work than any one person could do—but it would betray her patients and break the law. In order to ensure quality care, no one can legally bill Medicare and Medicaid for interpretations by a doctor who is not licensed in the United States or physically present in the country, Dr. Moore says. State medical boards may come after doctors who take the shortcut for patients covered by private insurers.

There is no guarantee the readers working for these companies would be licensed as doctors in India, either. “Any time you’re sending stuff over the Internet, you don’t really know who’s on the other end,” the Atlanta radiologist says. “Who’s actually sitting in front of the monitor, and where in the world are they? U.S. radiologists can outsource to India for pennies on the dollar, and who knows if [people reading the scans] have any training at all?”

Teleradiology is here to stay: Hospitals are not going to trade cutting-edge digital equipment for old-school films, nor will cash-strapped facilities hire round-the-clock radiologists. Still, administrators must be more aware of the tip-offs to fraud, experts say. In 2007, the Alabama State Board of Medical Examiners had sanctioned Dr. Reddy for allowing assistants to perform scans and invasive procedures they weren’t licensed to do. The Atlanta trial showed he claimed to have reviewed images while he was traveling on airplanes with no Internet access and to have seen 70,000 scans in eight months, a pace Anand calls “physically impossible.”

The American College of Radiology has urged all hospitals and imaging centers to ensure that offshore physicians meet the same standards met by U.S. doctors. This includes contracting only with teleradiology services that employ doctors who have hospital privileges and are licensed in the state. But mere credentials aren’t sufficient: Dr. Wong, who read one of Jennifer Drumm’s scans from Hong Kong, is licensed in Pennsylvania, but that didn’t prevent the crossed signals in her care.

What really makes a difference is teamwork, says Douglas K. Smith, M.D., president of Musculoskeletal Imaging Consultants in San Antonio. Superior teleradiology companies offer video conferencing between radiologists and clinicians, sometimes patching in the patient. Dr. Smith’s company also developed software that allows clinicians to review the work of different radiologists and matches them with those they like; he envisions a future in which patients could also weigh in. “You can outsource images to the lowest bidder, which increases the disconnect with patients, or you can use technology to build a closer relationship,” he says.

Patients can encourage more back-and-forth, too. At the time a scan is taken, Dr. Moore suggests, ask, Where will my study be interpreted? Is the radiologist credentialed to read it? Is the facility accredited by a national agency such as the Joint Commission? You can also find out who read your scan by asking for a copy of her report. Then, if symptoms persist and you suspect you’ve been misdiagnosed, you can talk to your physician about getting a second opinion from a different source.

You can also quiz your M.D. on whether she’s talked to the radiologist, reinforcing the idea of communication. Dr. Smith suggests having your doctor write a brief summary of your case—symptoms, meds, diagrams of where you hurt—and asking the person taking your images to scan it into the computer for the radiologist. “We like to put together the history,” he says.

Tracey Ehlen and Scott DeNoyer remain crushed that they lost their mother to miscommunication. Ehlen is left with memories—the pet names only her mother called her, how her mom sold her home to help pay for Ehlen’s wedding and DeNoyer’s house—and also regrets. “You take the physician’s word and assume they know what they’re talking about,” she says. Her brother agrees. “I assumed the [radiologist] would be someone at the hospital who knew the entire background,” he says. “I kick myself for not speaking up.”

Your scans say you’re fine. Are you?

YOU FEEL… Foot, leg or hip pain that worsens with activity

YOUR DOCS USE… X-ray, which many patients will initially receive to rule out a fracture or arthritis

WHY THE FIRST READ MIGHT FAIL: “Early on, X-rays can miss 75 to 80 percent of stress fractures,” says Lisa Callahan, M.D., medical director of the women’s sports medicine program at the Hospital for Special Surgery in New York City. Rest two weeks, and if pain persists, discuss an MRI; it may spot cellular changes that precede a break.

YOU FEEL… A lump, sharp pain, bleeding or skin changes in breasts

YOUR DOCS USE… Mammogram, although women may have to wait until after their period to see if the lump persists

WHY THE FIRST READ MIGHT FAIL: Even among women who get a mammo and an ultrasound, a small number of cancers aren’t caught, says Dr. Koenigsberg, chief of the division of breast imaging at Montefiore Einstein Center for Cancer Care in Bronx, New York. If symptoms stick around, see a breast surgeon, who can do a biopsy.

YOU FEEL… Sudden confusion, headache, nausea or numbness

YOUR DOCS USE… Head CT, often the first-line test for issues such as aneurysms, migraines or tumors

WHY THE FIRST READ MIGHT FAIL: It could be a stroke, even if you’re young. “If symptoms are real but the imaging results don’t match, you have to move on from CT to the next level, which is an MRI,” says Laurie Loevner, M.D., professor of radiology at the University of Pennsylvania. Don’t hesitate to pipe up: Stroke requires treatment ASAP.

YOU FEEL… Neck pain and muscle spasms after an accident

YOUR DOCS USE… X-ray or MRI, to try to determine if you have a herniated disk in your neck or merely a strain

WHY THE FIRST READ MIGHT FAIL: “Muscle spasm holds everything rigid, so you can have a herniation but not see it on an X-ray,” says musculoskeletal radiologist Douglas K. Smith, M.D., of San Antonio. MRIs may also miss disks that bulge when you bend your neck. If you feel neck or arm numbness, ask about an MRI done with the neck inverted. —Sara Austin